Abstract
A new low-nickel steel plate has been developed for liquefied natural gas (LNG) tanks, which has excellent performances equivalent to those of the conventional 9%Ni steel under ultralow temperature. In this study, properties of the developed steel plates were evaluated to assess its applicability to LNG storage tanks. The brittle crack initiation properties of the developed steel plates and its welded joints were evaluated by CTOD tests and cross weld notched wide tests. Duplex ESSO tests were conducted to demonstrate brittle crack arrestability of the base plate. Fatigue properties and physical properties were also examined. Additionally, safety evaluations for applicability of the developed steel plate to LNG tanks were discussed based on fracture mechanics.